Field of the Invention
The present invention relates to a technique for controlling a zoom magnification by detecting a subject image from an image.
Description of the Related Art
There has been conventionally known an imaging apparatus having a function of enabling a photographer to easily take a photo of himself or herself (so-called self photographing), by performing image capturing with a monitor oriented toward a barrel lens direction using a tilt movable liquid crystal monitor or the like. In addition, there is an imaging apparatus having a function of performing optical zooming by driving a zoom lens and a function of performing electronic zooming by magnifying a part of a captured image. Furthermore, there is known an imaging apparatus having an automatic zooming function of automatically changing a zoom magnification according to the detection information of a subject.
Japanese Patent Application Laid-Open No. 2012-95019 discloses the configuration of a camera equipped with an automatic zooming function of keeping the size of a subject constant. In the automatic zooming function disclosed in Japanese Patent Application Laid-Open No. 2012-95019, a photographer selects a reference composition from among a plurality of options such as “face closeup”, “upper body closeup”, and “entire body”, and automatic zooming control is performed so as to keep the size substantially matching a reference subject size predefined for each reference composition. The photographer performs an operation of issuing an image capturing instruction at a timing at which a field angle matching the set reference composition is achieved, so that a captured image with a desired composition can be obtained.
Nevertheless, in self photographing, the above-described image capturing method may fail to obtain a captured image with a composition desired by the photographer in some cases. FIGS. 8A and 8B are diagrams illustrating the states of self photographing. As illustrated in FIG. 8A, a photographer checks, using a display unit 109, whether a desired composition is achieved through automatic zooming control, and shifts to image capturing preparation at a timing at which it can be checked that the desired composition is achieved. At this time, if the photographer desires to capture an image in which the photographer looks toward a camera direction, the photographer needs to start an image capturing operation after turning his or her eyes toward the direction of a digital camera 100 (the direction of an imaging optical system) as illustrated in FIG. 8B, from the state in which the photographer looks at the display unit 109 for checking the composition.
Nevertheless, during a period from the image capturing preparation to the image capturing, the composition may shift due to hand shake or the like. Furthermore, if the photographer looks away from the monitor for capturing an image in which the photographer looks toward the camera direction, image capturing may be performed without the photographer realizing that the composition has shifted. As a result, although the photographer has checked at the time of image capturing preparation that the desired composition has been achieved, a captured image with a desired composition may fail to be obtained. For example, a subject may go out of a frame, or a subject size within a screen may change to be larger.